Domain Testing: Divide and Conquer - Testing Education

Variable Dimension Equivalence
classes
User name
Length All values
having lengths
in the range of 5
to 15
Type of
Characters
All values
having lengths
outside the
allowed range
All values
containing
allowed
characters
All values
containing at
least one
character that is
NOT allowed.
Test cases
(Best representatives)
A user name having length of:
1) 5
2) 15
A user name having length of:
1) 4
2) 16
3) 0
4) Max-length at the system level
5) Max-length + 1 at the system level
Digits:
A user name containing
1) 0 (ASCII code 48)
2) 9 (ASCII code 57)
Lowercase characters:
A user name containing
1) a (ASCII code 97)
2) z (ASCII code 122)
Digits:
A user name containing
1) character with ASCII code 47
2) character with ASCII code 58
Lowercase characters:
A user name containing
1) a character with ASCII code 96
2) a character with ASCII code 123
3) character corresponding to ASCII
128 of the extended ASCII set
Risks
1) Failure to process user
names correctly, that
have their lengths within
the allowed range.
2) Mishandling of lower
and upper boundary
values.
1) Mishandling of user
names that have their
lengths outside the
allowed range.
2) Mishandling of user
names just beneath and
beyond the lower and
upper boundaries
respectively.
3) Mishandling of too
small, too long strings
and beyond.
1) Failure to process
allowable characters
correctly.
2) Mishandling of lower
and upper boundary
values.
1) Mishandling of user
names that have nondigits
2) Mishandling of user
names that contain
characters that are NOT
allowed.
3) Mishandling of values
just beyond lower and
upper and boundary
values respectively.
4) Mishandling of
characters from the
extended ASCII set.
5) Mishandling of value
just beyond the upper
boundary of the standard
ASCII set.